Rough-legged Hawks are migratory birds that spend their winters in open country across much of the United States, including Oregon. They are distinctive for being one of the few hawk species with legs feathered all the way to their toes, an adaptation for their Arctic breeding grounds. Like many raptors, they exhibit reversed sexual dimorphism, meaning females are generally larger than males. Beyond size, there are also some subtle but helpful plumage differences, especially in light morphs.

General Appearance (Male and Female):
Size & Shape: Rough-legged Hawks are fairly large buteos with relatively long, narrow wings and a somewhat long tail compared to other Buteo hawks. Their flight is often buoyant, and they are well-known for their hovering behavior while hunting.
Feathered Legs: A key identifying feature for both sexes and all ages is their feathered legs, which appear "rough" due to the dense feathering extending down to their feet.
Dark Wrist Patches: In flight, both sexes typically show distinctive dark patches at the "wrists" (carpal joint) on the underside of their wings.
Tail: The tail is typically pale at the base with a dark band at the tip, though the specifics of the banding differ between sexes and age classes.
Color Morphs: Rough-legged Hawks come in both light morph and dark morph variations. While dark morphs are mostly dark brown and can be challenging to differentiate by sex, the light morphs show more distinct sexual differences in plumage.

Distinguishing Male and Female Rough-legged Hawks in Oregon (Light Morphs):
The most reliable ways to differentiate male and female Rough-legged Hawks, particularly in their more common light morph, involve a combination of size and plumage patterns:

1. Size:
Females are noticeably larger and heavier than males. While there's overlap in individual measurements, if you see a pair together, the female will appear significantly bulkier.
Typical measurements:
Males: Length around 18-22 inches (46-56 cm), wingspan around 48-54 inches (122-137 cm), weight 1.6-2.4 lbs (715-1100 g).
Females: Length around 19-23 inches (48-59 cm), wingspan around 50-56 inches (127-142 cm), weight 2.0-3.0 lbs (900-1400 g).

2. Belly Band: This is often the most useful plumage difference for light morph adults:
Female Light Morphs: Tend to have a more extensive and solid dark belly band (or "belly patch") that contrasts strongly with their pale head and breast.
Male Light Morphs: Often have a similar pattern but with a more mottled or streaky belly band, or the dark markings on the belly may be less distinct, sometimes appearing as a "bib" on the upper chest with a clearer U-shaped area below it. Males tend to have streakier underparts and barred legs.

3. Tail Banding (Adults):
Female Adults: Usually have one wide, dark subterminal band on an otherwise whitish tail. The lower half of their whitish tail may appear dusky.
Male Adults: Often show multiple, thinner, dark bands on their white tail, in addition to a broader subterminal band. The tail can appear grayer above than the female's.

4. Head/Breast Color (Adults):
Female Adults: Often have a paler head and breast that provides a good contrast with their dark belly patch.
Male Adults: May have a slightly darker or more streaky head and breast compared to the female.

Juvenile Rough-legged Hawks (Both Sexes):
Juvenile Rough-legged Hawks (both male and female) have some distinct characteristics that make them different from adults, and they can be challenging to sex:

Eyes: Juveniles typically have light-colored eyes (pale yellow to yellow-brown), which darken to dark brown as they mature into adults.
Belly Band: Juvenile light morphs often have a broad, smudgy dark belly band or "vest" that is similar to a female's but can be less defined.
Tail: Juveniles have a tail that is white at the base with a diffuse, smudgy dark tip rather than the sharply defined black bands of adults. They also often show pale "windows" in their outer primaries when in flight.